Arch construction for furnaces



July 31, 1923. 3,463,241

F. B. BIGELOW ARCH CONSTRUCTION FOR FURNACES Filed April 9, 1920 atented July 31, 1923.

FRANK B. BIGELO'W, OF DETROIT, MICHIGAN, ASSIGNOB TO MURPHY IRON WORKS, OF DETROIT, MICHIGALLA CORPORATION OF MICHIGAN.

' ARCH CONSTRUCTION FOR FURNACES.

Application filed April 9, 1920. SerialNo. 372,419.

To all whom it may concern y Be it known that I, FRANK B. Brennow, a citizen of the United States, residing at'Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Arch Constructions for Furnaces, of which the following is a specification.

My invention concerns improvements in the fire-brick roofs or arches over the combustion chambers or compartments of furnaces, such as are ordinarily associated with steamboilers for the production of heat or power. One salient feature of the invention is the supporting or suspension of the arch bricks from above by extremely simple and economical means and in such a way that they will remain in contact throughout the entire range of temperatures to which they are subjected in service, and hence prevent the product-ion of cracks or crevices between them through which air might undesirably pass to the fuel-chamber. This suspension arrangement permits the ready insertion of a new brick to take the place of a damaged or injured one without disturbing the arch as a whole and without interfering with the other bricks.

A further leading aim of the invention is the provision of a construction of this general character which permits the replacement of one or more arch bricks without requiring the closing down of the furnace, the brick substitution being efl'ected during the substantially normal operation of the furnace. The brick or arch supporting means may also be employed as air-conducting means, the air being delivered to the firechamber to facilitate the combustion and at the same time acting as a cooling medium for the support.

To those skilled in this art the manner of attaining these and various other features of novelty and advantage will be understood and appreciated from a consideration of the preferred embodiment of the invention illustrated in the accompanying drawings forming a part of this specification and described in detail below. In the various views of the drawing like reference characters refer to the same parts.

In the drawing:

Figural is a partial transverse vertical section through a furnace of the Murphy type equipped with the improved means for suspending the arch, this section being taken on line 11 of Figure 2, some of the bricks being broken away to more clearly show the hanger construction;

Figure 2 is a longitudinal vertical section on line 2-2 of Figure 1; and

Figure 3 is a fragmentary enlarged vertical section through the rear portion of the arch to show more clearly the manner of suspension and retaining in place of the rear end bricks or blocks.

The particular furnace shown, equipped with an arch embodying this invention, is one of the well-known Murphy type with a V-shape grate 10, opposed fuel magazines 11, 11, disposed along the sides of the firechamber and provided with side'wise-acting,- reciprocating fuel pushers or stoking boxes 12, which feed the fuel descending from the magazines across the coking-plates 13 on to the upper portions of the grate, down which it gradually travels partly by reason of gravity and partly due to the movements of certain of the grate-bars comprising the grate, all this being old and well-known construction.

'Three, or any other suitable number of spaced horizontal lI-beams 14, 15, and 16 extend across the furnace above the arch 17 which in this instance is fiat, but may, of course, be of any desired shape, and are supported attheir ends u on extensions 18 and 19 of the inner side-wa is of the pair of magaz'ines 11, 11 to which they may be fastened by any suitable devices such as angle brack ets 20. The webs of these three supporting bars or beams are apertured in alignment at a plurality of points for the reception of a corresponding number of horizontal tubes or pipes 21, each of which extend into an apertured boss 22 in the furnace front-plate and project rearwardly beyond the innermost bar or beam 16. p

The arch proper is composed of a plurality of refractory bricks or blocks 23, arranged in longitudinal and transverse rows, the bricks contacting with one another to maintain the arch substantially air-tight and contacting with the front wall 24;, being thus maintained against substantial displacement, but capable of slight shifting under unequal expansion and contraction. As is shown, one supporting pipe is provided for cut groove 25 across its top face and extended transversely of the combustion "chamber and accommodating the enlarged foot 26 of an apertured supporting-shoe 27, the foot being of substantially the same shape in cross-section as the groove. An eye of such shoe receives the lower bent hook end of a hanger rod 28, the upper end of which is hook-shaped and hangs on the correspondingsupporting pipe 21. As is clearly shown, the two hook-shaped ends of the rod are disposed in planes at right-angles to one another. the one end to hang over the supporting-pipe, the other end to engage the hangershoe.

At each side of the combustion-chamber I provide a row of arch-plate bricks 29, 29, of somewhat difierent construction, these rows being below the arch as shown in Figure 1, and held in position by any approved means, leaving, as is customary, a series of air-passages between them and the magazines.

As is shown in Figure 2, the rear brick 30 of each row of the arch proper is. some what elevated above the other brick of the arch by reason of a shorter supporting rod and is of special construction, having a rounded rear surface 31 and an upwardly extended portion 32 acting to partially close the rear end of the chamber above the arch. Above the part 32 another brick or block 33 is employed, being mounted on the rear end of the corresponding pipe 21 and recessed at 34 for the reception of'that part of the pipe. Block 33 is held in position on the supporting tube or pipe by a cast-iron plug 35 equipped with an extension-hook 36 which by engagement with a hole in the pipe maintains the block in proper position thereon.

The space in the brick or block at the rear of the plug is sealed or filled with any suitable refractory material 37 such as a mixture of ground fire-brick and clay. The members 30 and 33 completely seal the chamber above the arch referred to which is closed on top by fire-brick tile 38 carried on T-bars 39, the tile being covered by sheetsteel plates 40. The pipes or tubes 21 are preferably perforated at 41 near their rear ends and thus assist in carrying air through the front plate of the furnace into the desired portion of the compartment above the arch from which, as is customary, it flows down into the fire-chamber through the passages between the arch-plate bricks and the magazines. This air supplements that otherwise fed to the combustion chamber and is heated more or less as it travels through the pipes and at the same time aids in keeping the pipes and hangers cool.

It will be observed that the supports for the arch-bricks, including the rear end brick 30, are above their centers of gravity, and they are arranged to contact with one annaeaaei other when the furnace is cool. As it heats up these bricks may shift position slightly to compensate for expansion and possibly iirregular heating, but they at all times maintain contact with one another, thus preserv ing the substantially air-tight construction of the arch. When the furnace cools the bricks by reason of their pivotal mountings are free to swing back into normal position maintaining contact with one another.

Tn case one of the bricks of the arch becomes injured or burned sufficiently to re quire replacement, the appropriate coverplate 40 and tile 38 are lifted ofl, the hang-en rod 28 of the particular brick isreleased or disconnected from the pipe and the shoe 2? and by any suitable means, such as a rod or bar, the remnants or pieces of the brick are pushed or forced downwardly into the corn bustion chamber from which they may readily removed. This dislodgement oi the parts of the damaged brick can be acco plished without substantial trouble 1" the furnace heat because the gap in the caused by the damaged brick or the he created by the removal of the brick induces a downward flow of air-through such aper ture away from the workman by reason the furnace draft. This enables the open ator to carry on the replacement operation without real annoyance or difiiculty because I of the heat of the furnace. The injured brick having beenv thus gotten rid of, the new brick mounted on a hanger is lowered into place and its supporting-rod hung on the pipe. Then the cover tile and metal plate are replaced. This replacement operation can, therefore, be performed during the usual operation of the furnace and without disturbance of its normal functioning.

Tn case one of the bricks below one of the supporting cross l-beams is required to be replaced it may be necessary to take out an adjoining brick to enable the first one to be llll llti

and essence of the invention and without the sacrifice of any of its substantial benetits and advantages. It will be furthermore appreciated that by making the hangerrods 28 of difl'erent lengths the arch may be given any contour or curvature found to be necessary or desirable.

I claim:

1- na susp nded-arch construction for Mill furnaces of the character described, the combination of a. plurality of bricks constituting a rtion of the arch, a plurality of indepen ent hangers each supporting a brick of the arch from above, and a supportingpipe above said arch and common to said hangers, substantially as described.

2. In a suspended-arch construction for furnaces of the character described, the combination of a plurality of bricks constituting a rtion of the arch, a plurality of indepen ent hangers each supporting a brick:

of the arch, from above, a supporting-pipe above said arch and common to said hangers, and means to permit a cooling medium to flow through said pipe,-substantially as described. I

3. In a suspended-arch construction for furnaces of the character described, the combination of a plurality of bricks constitutingthe arch, a plurality of spaced supportingpipes above the arch and adapted to convey air to assist in the combustion, and a plurality of independent hangers carried on each of said pipes and each supporting 'a single brick of the arch, substantially as described.

4. In a suspended-arch construction for furnaces of the character described, the combination of a plurality of bricks'constituting the arch, a plurality'of spaced supportingpipes above the arch disposed longitudinally of the arch and adapted to convey air to assist in the combustion, and a plurality of independent hangers carried oneach of said pipes and each supporting a single brick of the arch, substantlally as described.

5. In a suspended-arch construction for furnaces of the character described, the

l described.

combination of a plurality of bricks. constituting the arch, a plurality of spaced supporting-pipes above the arch, a plurality of independent hangers carried on each of said pipes and each supporting a single brick of the arch, and means to convey a coolin me-' furnaces of thecharacterdescribed, the com;

bination of a plurality of bricks constitut- 'a rear-wall brick mounted direct in the arch, arran ed in rows longitudi- .na ly and transverse y of the arch,'a supporting-member above the arch for each of such longitudinal rows, a supporting-shoe for each brick disposed transversely of the arch,

a plurality of independent supporting rods each detachably connected to one of said shoes and mounted on the corresponding supporting-members and end wall bricks mounted directly on the rear ends of said supporting members, substantially as described.

8. In a suspended-arch construction forfurnaces of the character described,'the combination of a plurality of bricks constituting the arch arranged in rows longitudinally and transversely of the furnace, a supporting-member above the arch for each pf such longitudinal rows, an apertured supportingshoe for each brick disposed transversely of the arch, a plurality of supporting-rods each having hook-shaped ends at right-angles to one another, and each adapted to detachably engage one of said shoes and one ofsaid supporting member and end wall bricks mounted directly on the rear ends of-said supporting members, substantially as described. I I

9. In a suspended-arch construction for. furnaces of the characterdescribed, the combination of a'plurality of bricks constituting a portion of the main-body of the arch, a support above and disposed longitudinally of the arch, hangers supporting the bricks individually on and below said su port, and y on said support, substantially as described.

10. In a suspended-arch construction for furnaces of the character described, the combination of a row of bricks constituting a.

portion of the arch, a support above and disposed longitudinally of said row of ,said bricks, hangers supporting said bricks individually on and below said su port, the rearm'ostbrick having an upward 'extension forming part of a back-wall, and another brick constituting a part of said wall mounted directly on said support, substantially as described. 11. In a suspended-arch construction for furnaces of-the character described, the combination of a plurality of bricks constitutin'gthe main body of the arch, a tubular support above said bricks, hangers individ ,ually supporting the bricks on said tubular I support, and a rear wall brick mounted di- J rectly on said tubular support andhavin' means disposed inside such support for hold ing the brick in place, substantially as described.

FRANK B. BIGEW." I 

